Hello,
I've recently purchased a 1967 V6 3speed Ford Mustang and the car drove great without any noticeable issues. The car is stock. However, as of today, I had a hard time starting the car after leaving my local gym. The previous owner suggested that I turn the key and give the car a little gas simultaneously with my foot on the clutch and the car would start. This method worked up until today.
Tonight I turned the key, gave it some gas with my foot on the clutch and the engine would not roll over. The starter sounded strong but the engine was not catching to roll over. After trying a few times, I sat and waited a minute and tried again giving it more gas this time and she finally rolled over. I put her in reverse then drove away. 1 minute later after idling a stop sign in neutral, I put her in 1st gear to take off and she stalled. It felt as if the engine was breathing or idling in a weak fashion. Again, I had a battle getting the car to roll over. The rest of the way home I didn't take any chance and kept the rpm's high by staying in gear.
I'm not sure if its the carburetor, fuel pump, alternator, battery or starter but I really want to gt this car running more efficiently.

Check to see if your carburetors are affected by humidity, moisture, cold and heat conditions, as well as debris particles that entered the jets and small orifices. Any number of problems with carburetors could cause rough idling or no-start conditions. Then check your fuel pump. A bad fuel pump may not pump the fuel into carburetors. Finally check your sparks and clean them. Change the plugs if necessary. Also, make sure that the ground wire to the battery is good.

I lean with Logan, routine maintenance on the older cars include plugs, points, condenser, and wires on a regular basis, usually about 10k miles for the points and condenser, the new plugs may get longer life than those made in '67. If someone's converted to electronic ignition, disregard.

Ever notice that there's so many high performance parts available for GM products?

^ . Points , condensors in cars , those were the good old days when we used repair / service cars and parts !! Points were notorious , with pitting , burning on contacts closing the clearance gap .You also get the contacts "blueing " which is usually a sign condensor failure and too fat a spark .